Princeton Prof's Strange Ancestors

At one time, Princeton was considered a top-tier university.

Things change.

A Scientific American essay deemed “embarrassing” and “pseudo-scientific” is facing backlash after insisting human sex is “not binary,” while arguing claims to the contrary “are not about biology but are about trying to restrict who counts as a full human in society.”

The Monday article authored by Agustín Fuentes, a professor of anthropology at Princeton University, bears the blunt title, “Here’s Why Human Sex Is Not Binary.” ...

Oh.

See, there's proof!!

...According to him, “the production of gametes does not sufficiently describe sex biology in animals, nor is it the definition of a woman or a man.”...

Why not?  Here's what the professor has to say:

...While most animal species fall into the “two types of gametes produced by two versions of the reproductive tract” model, many don’t. Some worms produce both. Some fish start producing one kind and then switch to the other, and some switch back and forth throughout their lives. There are even lizards that have done away with one type all together (sic). Among our fellow mammals, which are less freewheeling because of the twin constraints of lactation and live birth, there are varied connections between gametes and body fat, body size, muscles, metabolism, brain function and much more...

So the professor believes that he is descended from lizards?  Fish?  Worms?

Based on his writing, that's probably right.